#904 AHU/Chiller Outstanding Issues

Brian Frank Thu 15 Apr

While flushing out the proto points for different equipment, there are some topics (some new, many old) that require deeper work and community involvement.  

I think most of these topics fall into the domain of Standing AHU WG, so I'm going to suggest that as the vehicle of resolution. Plus there are a couple chiller posts for that Chiller WG.


The thought is that we should consider filters as first-class equipment, and then define the points which are associated with filters.  That would include dirty sensors or differential pressure sensors.  Then we could use the children flattening

For reference here is how the filter tag is defined in Haystack 3.


There are a huge number of points which from a human language perspective might benefit from a min or max tag.  A classic example is this proto:

  // current proto
  zone air co2 concentration sp point

  // but should it be this?
  zone air co2 concentration max sp point


Do we need to expand the pressure tag to be more specific to cover static, dynamic, total pressure?

Two Pipe Systems

How should we tag coils and valves for two-pipe systems which share a single set of pipes for cooling and heating depending on the season.  This has been discussed at length before, but we need finalize the solution.

Fan Placement

Cory posted a proposal to expand fan tags for placement, etc which needs to be evaluated.

Reheat VAV

We need a new VAV type that is non-powered, but with reheat.  


Separately under the Chiller WG, there have been a few significant proposals:

Jay posted a proposal to break up chiller into its subparts (evaporator, compressor, etc).  Technically this one would be under the Chiller WG

David Waterworth posted a set of missing points.

Jay Herron Fri 23 Apr

Thanks for this list Brian. I'll pull coordinate a time for the AHU working group to meet and discuss these items.

For anyone in the community that has thoughts on these topics, please come join the AHU Standing Working Group so your voice can be heard! We'd love the input!

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